PAES terms

• Biogas plant


  Plant used to process animal wastes or manure to produce biogas and sludge consisting of an inlet/mixing tank, digester, gas chamber and outlet/sludge tank
• Integrated plant


  Biogas plant where the digester and gas chamber form one unit
• Split type plant


  Digester and gas chamber form separate units
• Multi digester


  Plant with series of digesters
• Floating type


  Plant consisting of digester and a moving, floating gasholder that either float directly in the fermenting slurry or in a separate water jacket
• Fixed type


  Closed digester with an immovable, rigid gas chamber and a displacement pit
• Balloon type


  Plant consisting of a heat-sealed plastic or rubber bag (balloon), combining digester and gasholder
• Collecting tank


  Holding tank; chamber where manure and water are collected, stored and separated from heavy and nonbiodegradable materials before feeding them into the digester
• Inlet pipe


  Serves as conveyor of the manure-water mixture or slurry from the mixing tank to the digester
• Digester


  Any water and air tight container designed for the process of anaerobic microbiological degradation of organic matter into which the slurry is introduced for digestion and methanization
• Baffle board


  Division in the digester that prevent the slurry from premature exit into the sludge/outlet tank
• Stirrer


  Agitator; mechanical device inside the digester used to stir the slurry
• Gas chamber


  Space inside or outside the digester for the collection and storage of biogas
• Gas holder retainer


  Cantilever beam that holds the gasholder/movable cover in position at the desired biogas pressure
• Outlet pipe

  Serves as conveyor where the effluent or the slurry is forced out
• Backfill


  Layer of compacted soil and gravel to support the digester wall
• Loading rate


  Amount of slurry fed per unit volume of digester capacity per day
• Substrate


  Organic material used to produce biogas
• Seeding


  Adding or introducing anaerobic bacteria to the digester
• Slurry


  Mixture of manure and water
• Freeboard


  Difference in height between the digester wall and the filling line
• Filling line


  Level of slurry when the digesters is at full load
• Retention time


  Average period that a given quantity of slurry is retained in the digester for digestion
• Toxic materials


  Materials that inhibit the normal growth of pathogens in the digester such as mineral ions, heavy metals and detergents
• Methanization


  Various processes that take place among the methanogens, non-methanogens and substrates fed into the digester as inputs
• Methanogens


  Anaerobic bacteria that act upon organic materials and in the process, produce biogas
• Mesophilic temperature range

  Temperature range of 20 oC – 40 oC where mesophilic bacteria operates
• Gas production rate


  Amount of biogas produced per day per cubic meter of slurry
• Biogas


  Mixture of gas (composed of 50 to 70 percent methane and 30 to 40 percent carbon dioxide) produced by methanogenic bacteria
• Scum


  Layer of floating material (mainly fibrous) on the slurry
• Sludge


  Settled portion or precipitate of the slurry; a mud-like, semi-solid mass
• Effluent


  Residue that comes out at the outlet after the substrate is digested/processed inside the digester
• Feedlot


  Area with its physical facilities used for carabao fattening
• Carabao


  Philippine water buffalo or swamp buffalo
• Bull


  Breeding male of any age
• Calf


  Young male or female under one year of age
• Cow


  Mature female that has already calved
• Heifer


  Female between two to three years of age which has not given birth
• Corral


  Enclosure for confining and handling livestock
• Holding pen


  Pen for confining animals from the pasture